Rotary cutter for skiving or trimming machines.



M. T. DENNE.

ROTARY CUTTER' FOR SKIVING 0R TRIMMING MACHINES.

APPLICATION FILED JAN. 17, I914.

Patented June 26, 1917.

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aw 9 Mm MARK THOMAS DENNE; or RUSI-IDEN, ENGLAND.

ROTARY CUTTER FoR sxIvING R TRIMMING MACHINES.

Specification of Letters Patent. Patented June 26,1917.

Application filed anuary 17, Serial $12,819.

' tary Cutters for Skiving or Trimming Machines, of which the followingis a specification.

This invention has reference to improvements in and relating to rotarycutters for skiving or trimming machines, and it consists in thecombination of a cutter or knife made of thin ribbon of steel and anexpansible drum to carry said knife so that the knife or cutter may beeasily applied or removed by merely contracting the drum whereas whenthe cutter has been adjusted in position and the drum expanded saidcutter will be firmly held so as to be compelled to rotate with the drumand whereby the knife or cutter although made of thin ribbon steel willyet be maintained rigid and its lateral deflection prevented.

A constructional form of my invention is illustrated in the accompanyingdrawing, Figure 1 being a front view and Fig.2 a side elevational viewpartly in section.

In said drawing A indicates a bearing with which a suitable fra1nenotshownis formed or provided, and which supports a spindle or shaft B towhich rotary motion may be imparted in any usual suitable manner.

On one end of the spindle I mount a uasi expansion clutch comprising twomembers C and D. The member D is secured to the shaft in any suitablemanner for example by being screwed thereon to abut against a collarcl(which latter in conjunction with, say, another collar may serve toprevent axial movement of the shaft B) so as to be rotatable with theshaft and the other member, 0, is slidable on the shaft so that it maybe pressed or forced closer to or allowed to recede from the member D.

The member D is formed with slits or slots S of suitable dimensionsaround its periphery and it has a cylindrical outer bearing surface (Z.The inner surface of the peripheral part is made conical and the outerperipheral part of the'member C is made correspondingly conical so thatwhen the member C is pressed or forced against the member D the slottedportion will expand and the effective diameter of the member D will bethereby increased.

The knife or cutter E is made of thin ribbon steel the ends of which maybe brazed or welded together or it may be made by rolling on theprinciple of tire rolling. It is made cylindrical and snugly fits on thecylindrical bearing surface cZ/ whenthe member D is at itssmallerdiameter and said member is preferably formed or provided with ashoulder (l against which the inner edge of the knife or cutter abuts.

The member C may be pressed or forced against D by means of a nut 1*which is screwed on the end of the shaft B and which nut may be rotatedby a spanner or other project on both sides of the drum and have acutting edge on both sides thereof.

The cutter or knife although made of thin steel is quite rigid when thedrum has been expanded and is therefore much more practical for use inskiving, inseam trimming and the like than is an endless band saw orcutter in which the endless band is passed over two drums or pulleys andits lateral displacement to some extent prevented by means of guiderollers or the like.

Further the cost of my thin cylindrical cutter is much less than is thecost of the ordinary dished cutters heretofore generally in use inskiving and inseam trimming machines so that the renewals in the cutterswill very soon make my machine less expensive than those in usenotwithstanding some slight greater first cost.

In addition to the frictional engagement of the expanded drum with thecutter or knife to prevent relative movement I may provide the drum withpins or the like passing through or engageing with the knife wherebysuch relative movement will be absolutely prevented.

What I claim as my invention and desire to secure by Letters Patentis 1. A knife for skiving or trimming machines, comprising incombination a holder in the form of a drum capable of being freelyexpanded radially, a flexible cylindrical knife blade mounted on theperipheryor outer surface of the said drum with its cutting edgeprojecting laterally beyond the drum, and means for uniformly andradially expanding every point on the outer surface of the drum intocontact With the inner surface of the knife blade, so that the latter isconformed to the periphery or outer surface of the drum.

2. A knife for skiving or trimming machines, comprising in combinationan expansible holder in the form of a drum having a cylindrical outersurface and an inner conical surface, a flexible cylindrical knife blademounted on the periphery of the said drum With its cutting edgeprojecting laterally beyond the drum, and a member having a conicalsurface adapted to be forced against said inner conical surface of thedrum, said member being slidably and concentrically mounted Within thedrum and adapted to expand the drum against the knife blade When forcedagainst said inner conical surface of the drum.

In testimony whereof I have signed my name to this specification in thepresence of tWo subscribing Witnesses.

MARK THOMAS DENNE.

Witnesses:

' WALTER W. BALL,

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Iatents Washington, D. G.

